Igniting device for combustion tube wick burners



ERS

R. M. SHERMAN IGNITING DEVICE FOR COMBUSTION TUBE WICK BURN Filed NOV. 28, 1933 Sept. 1, 1936.

1- as oil) Patented Sept. 1, 1936 UNlTED STlE S IGNITIN G DEVICE FORCOMBUSTION UBE WICK BURNERS U A, v 2,053,113

Rallston M. Sherman, Glastonbury, Conn, assignor to The Silent Glow Oil Burner Corporation, Hartford, Coma, a corporation of Connecticut Application N0vember 28, 1933, Serial No. 700,126

3 Claims.

, This invention relates to burners and more particularly, though not exclusively, to what are termed combustion tube burners, to which liquid fuel (for descriptive purposes herein referred to is admitted and therein vaporized, the fuel vapor being burned in an overhead combustion chamber to which air is supplied through combustion tubes, herein in the form of perforated tubular walls.

One object of the invention, "among other things, is to provide a reliable but simple form of starting or igniting device through which initial lighting of the burner may be had by means of a pilot light established and maintained through the use of an independent supply of gaseous fuel.

r This and other objects of the invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawing:

Fig. 1 is a plan view of the burner embodying one form of the invention, the parts above the base being broken away;

Fig. 2 is a; central, sectional elevation of the same burner, taken on the line 22 -of Fig. 1, intermediate portions of the-combustion tubes beingbroken out; and Fig. 3 is a partial, detail, sectional elevation, on the line 3--3 of Fig. 1.

Referring to the drawing and to the embodiment of the invention which is here submitted for illustrative purposes, the burner is provided with a base in the form of a casting having .an outer, generally annular portion and an inner, concentric, annular portion spaced from but connected one to the other bya series of webs 3 and providing for an annular air admission opening |-5 between the two annular members of the base interrupted only by the webs. The inner, annular member is provided with a central air admission opening I! surrounded by an upstanding ring-like flange l9, the outer edge of the inner member also having an upstanding ring-like flange 2| (Fig. 1) spaced from but concentric with the flange Hi, the flanges l9 and 2|, together with the connecting bottom wall of the base casting, forming a relatively wide, annular compartment or channel 23. Oil is adapted to be delivered to the wide, annular channel by a pipe connection (not shown) opening through the bottom wall of the channel through the oil inlet opening 25' (Fig. 1).

The outer, annular member of the base casting presentsan outer, fuel channel 21 formed between the upright spaced flanges 29 and 3|, the outer channel being of lesser radial width than the channel 23. The outer channel 21 is connected to the inner fuel channel 23 by means of supply ducts 33 formed in the webs l3, so that free circulation of liquid or vaporized oil supplied through the vaporizing space takes place through both fuel channels. The top of the wide channel 23 is partly covered and closed by a removable annular cover plate 35 formed preferably of thin sheet metal, such as chromium steel, the inside edge of the plate having a down-turned flange to seat upon and within the upper edge of the base flange 9 with a preferably close fit.

The walls of the cover plate extend outwardly, and herein also downwardly, but are spaced vertically from the bottom of the channel 23 to provide an annular space through which vaporized oil may pass directly into the space between the flange 2| and theedge of the cover plate.

The edge of the cover plate has an out-turned lip on which there is supported .a perforated sheet metal cylinder 31 constituting the inner oneof a pair of combustion tubes. A similar but larger concentric cylinder 39 is removably seated on the outer shouldered edge of the, flange 2|, so that there is provided between the two cylinders an elongated combustion chamber 4| aligned with and constituting an extension of the outer uncovered edge of the wide fuel channel 23.- The two concentrically spaced, perforated sheet metal cylinders lt and 45 are likewise removably seated on the inner and outer shoulders, respectively, of the flanges 29 and 3|, providing between them a combustion chamber 41 having a relation to the outer fuel channel 21 similar to thatof the combustion chamber 4| to the outer portion of the channel 23. A..reinovable annular top plate 49 is provided with its edges resting on the tops of the sheet metal cylinders 39 and 53 to close the top of the annular air space therebetween, and a diskshapedclosure 5!, with its edges resting on the upper edges of the cylinder v31, is similarly provided to close the .top of the central air chamber, leaving, however, annular openings in the tops of the two combustion chambers 4| and. forthe escape ofthe products of combustion.

A burner of this type is commonly started by igniting an oil saturatedwick usually comprising a fabricated strip of asbestos,'the strip being out so as to restin the fuel space withits upper edge entered into the bottom of the overhead combustion chamber. In the illustrated burner, two such wicks 53 and 55 are shown, the first located in the inner fuel channel and the other in the outer fuel channel.

When the burner is to be started, oil is admitted through the inlet port 25 and enters the wide channel 23, flowing thereover to the outer portion thereof and through the ducts 33 into the outer fuel channel 21, penetrating the bottom edges of both wicks and saturating the bodies thereof. The wicks being then lighted, the burner begins to heat, and when the required vaporizing temperature is reached the liquid oil becomes vaporized on entering the channel 23 beneath the cover plate 35, the covered portion of said channel constituting a vaporizing space. Combustion is then carriedon to an increasing degree independently of the wick, and finally completely through the oil vapor passing from the combustion chamber beneath the edge of the cover plate into the inner combustion chamber and into the outer combustion chamber through the ducts 33, the inner wick being cut away (as indicated in Fig. 2) where it obstructs passage to those ducts and the wicks ceasing to function when the burner operates under full fire.

To ignite the wick automatically, as soon as the oil is turned on and the wick becomes saturated, igniting means is provided comprising a gaseous fuel pilot burner having a burner orifice positioned to apply its flame to the wick, together with means for delivering an independent supply of gaseous fuel to the burner.

To this end, each wick strip is separated by a space or gap and has its opposite edges abutting against an upright lug formed in the bottom of the channel. In the inner channel 23 the lug 51 extends laterally from the outer flange 2| into the channel for a short distance, and in the outer channel 21 the lug 59 extends entirely across the channel. Each lug (see Fig. 3) is provided with a vertical gas duct 61 connected at its bottom to a lateral duct 63 formed in an enlargement 65 on the bottom of the base, gaseous fuel being supplied to the duct 63 through the supply pipe 61 from any suitable sourceof gas supply under pressure, such as the ordinary illumintaing-gas, service main.

Threaded into the top of each lug, which is below the upper edges of the adjacent wick, is a burner tip 69 having one or more orifices, herein two, communicating with the upright duct 6| and preferably so disposed that when the'gas is ignited each burner orifice applies its flame to the edge of the adjacent wick.

Means are preferably provided for holding the opposite ends of each wick in an approximately fixed relation to the pilot flame. In the outer groove, the lug is so formed that the edges of the wick not only abut against the lug 59 but are guided or held in a definite position through a recess formed in the lug, into which the ends of the wicks fit. In the wider channel the opposite ends of the wick abut against the lug 51 and its sides are confined between the walls of the lug and the arc-shaped lugs H which project a short distance above the bottom of the channel and engage the inner side walls of the wick. Other similar upright positioning lugs 13 engage the inner walls of the wick at other points in the channel.

In starting the burner, the pilot light being permanently maintained. or having previously been lighted, oil is admitted to the base and as soon as the wicks become sufiiciently saturated, ignition of the wicks automatically takes place in both fuel channels. The position of the burner beneath the normal zone of combustion of the wicks and below the combustion chamber, protects the gas pilot burner against possible fouling through carbonization.

Pilot lighting provided by special pilot wicks, intended to maintain a pilot flame available when the burner is extinguished, has proved unreliable and unsatisfactory, since the intense heat of the base when the burner is under full fire, and which prevents the main wicks from retaining oil in liquid form, acts similarly on the pilot wick, or a suflicient portion of the length thereof, to prevent the re-establishment of the pilot flame when the burner is extinguished, by shutting off the oil supply. The use of an independent gaseous fuel supply for the pilot light, however, permits the latter to be maintained under all conditions of operation of the burner, unaffected by the intense temperature experienced under full fire operation, which condition tends to render oil fed pilot lights ineifective or unreliable.

While I have herein shown and described one specific embodiment of the invention, it is to be understood that extensive deviations may be made therefrom and various modifications employed in respect to the mechanical construction of the parts, and in respect to the type of burner to which the device is applied, all without departing from the spirit of the invention.

I claim:

1. A combustion tube burner of the type having a base presenting a fuel channel and spaced combustion tubes having formed between them a combustion chamber above and opening into said fuel channel together with means for introducing liquid fuel into said channel and a starting wick in said channel, said burner being of the type in which the base becomes highly heated during operation of the burner and vaporizes the fuel introduced into it so rapidly that said wick in full operation of said burner becomes dried and extinguished; said burner having combined therewith wick igniting means comprising a gaseous fuel pilot burner having a burner orifice positioned to direct its flame against said starting wick and heat the same and means for supplying gaseous fuel to said pilot burner, said pilot burner being spaced from the zone above said wick in which the wick flame burns, said combination providing for playing of said pilot flame upon said dried wick upon extinguishment of said burner from full operating condition, for prompt ignition of fuel absorbed by said wick upon introduction of fuel to said channel for avoidance of accumulation of carbon on the pilot burner tip as would occur if the latter projected into the wick flame zone, for maintenance of said pilot flame upon said burner reaching wick drying heat, and for maintenance of said pilot flame upon extinguishing of said burner.

2. A combustion tube burner of the type having a base presenting a fuel channel and spaced combustion tubes having formed between them a combustion chamber above and opening into said fuel channel together with means for introducing liquid fuel into said channel and a starting wick in said channel, said burner being of the type in which the base becomes highly heated during operation of the burner and vaporizes the fuel introduced into it so rapidly that said wick in full operation of said burner becomes dried and extinguished; said burner having combined therewith wick igniting means comprising a gaseous 76 fuel pilot burner having a burner orifice positioned to direct its flame against said starting wick and heat the same and means for supplying gaseous fuel to said pilot burner, said pilot burner positioned in said channel between opposite separated ends of said wick and spaced from the zone above said wick in which the wick flame burns and directing its flame against an end edge of the wick below the top edge thereof; said combination providing for playing of said pilot flame upon said dried wick upon extinguishment of said burner from full operating condition, for prompt ignition of fuel absorbed by said wick upon introduction of fuel to said channel even before it reaches the top edge of the wick, for avoidance of accumulation of carbon on the pilot burner tip, for maintenance of said pilot flame upon said burner reaching wick drying heat, and for maintenance of said pilot flame upon extinguishing of said burner.

3. A combustion tube burner of the type having a base presenting a broad, annular fuel channel and spaced combustion tubes having formed between them a combustion chamber above and opening into said fuel channeltogetherwithmeans for introducing liquid fuel into said channel and a starting wick in said channel, said channel having a covered portion extending laterally with relation to said combustion chamber, and said wick being located in the uncovered portion of said channel beneath the combustion chamber, said burner being of the type in which the base becomes highly heated during operation of the burner and vaporizes the fuel introduced into it so rapidly that said wick in full operation of said burner becomes dried and extinguished; said burner having combined therewith wick igniting means comprising a gaseous fuel pilot burner having a burner orifice positioned to direct its flame against said starting wick and heat the same and means for supplying gaseous fuel to said pilot burner, said pilot burner positioned in said channel between opposite separated ends of said wick and spaced from the zone above said wick in which the wick flame burns and directing its flame against an end edge of the wick below the top edge thereof, said channel being provided with means holding the end edge of said wick in predetermined relation to the flame of said pilot burner; said combination providing for playing of said pilot flame upon said dried wick upon extinguishment of said burner from full operating condition for prompt ignition of fuel absorbed by said wick upon introduction of fuel to said channel even before it reaches the top edge of the wick for avoidance of accumulation of carbonon the pilot burner tip, for maintenance of said pilot flame upon said burner reaching wick drying heat, and for maintenance of said pilot flame upon extinguishing of said burner.

RALLSTON M. SHERMAN. 

